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A teenager whose battle with a rare genetic condition that accelerates the aging process inspired professional athletes and spurred medical research was honored at his funeral on Tuesday.

Hundreds of 17-year-old Sam Berns' classmates turned out for the ceremony at Temple Israel in Sharon, Mass., New England Cable News reported. Patriots owner Robert Kraft was among the mourners. Berns died Friday of complications from Hutchinson-Gilford progeria syndrome, commonly known as progeria.

Berns was diagnosed with progeria when he was 22 months old. His parents Leslie Gordon and Scott Berns, who are doctors, founded the The Progeria Research Foundation after encountering a lack of information and research on the condition, which currently affects about 350 kids.

Their work is featured in the documentary "Life According to Sam." The exposure has brought greater recognition to the condition, which causes musculoskeletal degeneration, cardiovascular problems and other symptoms associated with aging.

Berns gave a TEDx speech in Washington D.C. about three months before his death explaining how he overcomes obstacles and laid out tips for leading a happy life.

"Even though there are many obstacles in my life, with a lot of them created by progeria, I don't want people to feel bad for me," Bern said in his TEDx speech. "I don't think about these obstacles all the time and I'm able to overcome most of them anyways."

He told the crowd that when his low weight prevented him from carrying a 40 pound snare drum for his high school marching band, he worked with an engineer to design a lightweight harness that would be easier for him to carry. The new apparatus weighed about 6 pounds, he said.

"Nothing was going to stop me from playing snare drum with the marching band in the half time show," Berns said.

Despite his condition, Berns was always upbeat. He gave the audience some advice on how to be happy. Focus on what you can do, rather than what you can't do, he said. Surround yourself with "people of high quality." And finally, he said, keep moving forward.

"I always try to have something to look forward to," he told the audience. "Something to strive for to make my life richer."

New England Patriots owner Robert Kraft mourned Berns' death, saying he had invited the teen to be the football team's honorary captain for Saturday night's playoff game against the Indianapolis Colts and was looking forward to spending time with him and his family.

"I loved Sam Berns and am richer for having known him," Kraft said in a statement Saturday.

Kraft, after being introduced to Berns and attending the HBO premiere of the documentary in New York in October, made a $500,000 matching pledge to the foundation. Berns, a sports fan who was invited to a Patriots practice that month, gave the players an impromptu motivational speech, the Boston Globe reported.

Berns was asked to name his favorite player. He didn't have one. It takes a team to succeed, he said.